FIG. 1 illustrates an example of a configuration of a frequency band of a carrier aggregation technology.
The carrier aggregation technology increases a data transmission rate by combining two or more component carriers and transmitting the combined component carriers over the broadband. The carrier aggregation technology has been introduced to High Speed Packet Access (HSPS) and Long Term Evolution of 3rd Generation Partnership Project (3GPP) corresponding to a cellular mobile communication standard. Referring to FIG. 1, the carrier aggregation technology of LTE may combine a maximum of five carriers of 20 MHz and use a maximum bandwidth of 100 MHz. Further, each of the component carriers is compatible with an existing single carrier and thus supports a terminal which supports only the single carrier. The carrier aggregation technology has an advantage in that it effectively increases a data transmission rate since mobile communication service providing companies re-use the existing LTE systems in an environment where it is difficult to possess successive bands of 20 MHz or more. One carrier aggregation technology is flexibly installed and compatible with the existing technologies. Further, the carrier aggregation technology can operate different networks according to respective carriers and easily implement a heterogeneous network.
A Base Station (BS) of the carrier aggregation mobile communication system allocates frequency and time resources of multiple carriers to users, thereby increasing a data transmission rate of the user. However, since coverage of a cell may vary depending on each carrier, each user can select a predetermined cell based on each carrier according to a position of the user and a channel environment and the BS is required to support scheduling of a predetermined combination of carriers and cells based on each user.